BOOK REVIEW IN COMMUNICATIONS
CHAPTER 12
Electronic Communications System By Wayne Tomasi
METALLIC CABLE TRANSMISSION MEDIA
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DEFINITIONS
TERMS
1)
Provides a conduit in which electromagnetic signals
are contained.
Guided Transmission
Media
2)
Emitted then radiated through air or a vacuum.
Unguided Transmission
Media
3)
Used to propagate electromagnetic signals between
two locations in a communications system.
Cable Transmission
Medium
4)
Most common means of interconnecting devices in
local area networks.
Cable Transmission
Systems
5)
Metallic conductor system used to transfer electrical
energy from one point to another using electrical
current flow.
Transmission line
6)
Two basic kinds of waves.
longitudinal and
transverse
7)
The rate at which the periodic wave repeats.
Frequency
8)
Currents that flow in opposite directions in a
balanced wire pair.
Metallic circuit currents
9)
Currents that flow in the same direction.
Longitudinal currents
10)
Cancellation of common mode signals.
Common mode rejection
11)
One wire is at the ground potential, whereas the
other is at signal potential.
12)
A circuit device used to connect a balanced
transmission line to an unbalanced load.
Prepared By : MA. ELAINE L. CORTEZ
Single-ended or
unbalanced
balun
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BOOK REVIEW IN COMMUNICATIONS
Electronic Communications System By Wayne Tomasi
14)
Most common metallic cables used to interconnect
data communications systems and computer
networks.
Parallel-conductor
transmission lines and
coaxial transmission lines.
15)
Formed by twisting two insulated conductors around
each other.
Twisted-pair
16)
Types of twisted pair.
17)
Coupling that takes place when a transmitted signal
is coupled into the received signal at the same end
of the cable.
Near-end crosstalk
18)
Standard color code specified by the EIA for CAT-5
cable.
Pair 1: blue/white stripe
and blue
Pair 2: orange/white
stripe and orange
Pair 3: green/white strip[e
and green
Pair 4: brown/white stripe
and brown
19)
Woven into a mesh.
Braid
20)
Name given to the area between the ceiling and the
root in a single-story building or between the ceiling
and the floor of the next higher level in a multi-story
building.
Plenum
21)
Used for high data transmission rates to reduce losses
and isolate transmission path.
Coaxial
22)
Refers to the woven stranded mesh that surrounds
some types of coaxial cables.
Shielding
23)
One layer of foil insulation and one layer of braided
shielding.
Prepared By : MA. ELAINE L. CORTEZ
Unshielded twisted pair
and Shielded twisted pair
Dual shielded
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BOOK REVIEW IN COMMUNICATIONS
Electronic Communications System By Wayne Tomasi
Rigid air-filled; solid
flexible
24)
Types of coaxial cables.
26)
Uniformly distributed throughout the length of the line.
Distributed parameters
27)
Transmission characteristics of a transmission line.
Secondary constants
28)
Impedance seen looking into an infinitely long line.
Surge impedance
29)
Expressed the attenuation and the phase shift per
unit length of a transmission line.
Propagation constants
30)
Ratio of the actual velocity of propagation of an
electromagnetic wave through a given medium to
the velocity of propagation through a vacuum.
Velocity factor.
31)
Relative permittivity of a material.
Dielectric constant
Conductor loss, radiation
loss, dielectric heating
loss, coupling loss and
corona
32)
Several ways in which signal power is lost.
33)
Voltage that propagates from the source toward the
load.
Incident voltage
34)
Voltage that propagates that propagates from the
load toward the source.
Reflected voltage
35)
Transmission line with no reflected power.
Flat or non resonant line
36)
Vector quantity that represents the ratio of reflected
voltage to incident voltage or reflected current to
incident current.
Reflection coefficient
37)
Incident power is absorbed by the load.
Prepared By : MA. ELAINE L. CORTEZ
Matched line
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BOOK REVIEW IN COMMUNICATIONS
Electronic Communications System By Wayne Tomasi
38)
Incident power returned (reflected) to the source.
Unmatched or
mismatched line
39)
Two travelling waves set up an interference pattern.
Standing wave
40)
Ratio of the maximum voltage to the minimum
voltage or the maximum current to the minimum
current of a standing wave on a transmission line.
Standing-wave ratio
41)
Used to matched transmission lines to purely resistive
loads whose resistance is not equal to the
characteristic impedance of the line.
Quarter-wavelength
transformers
42)
A technique that can be used to locate an
impairment in a metallic cable
Time domain
reflectometry (TDR)
43)
Return signal.
44)
Simply a flat conductor separated from a ground
plane by an insulating di-electric material.
Microstrip
45)
Simply a flat conductor sandwiched between two
ground planes.
Stripline
Prepared By : MA. ELAINE L. CORTEZ
Echo
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